Improvement in steam-boiler furnaces



` cording to my invention.

NITED STATES PATENT OFFICE.

IMPROVEMENT IN STEAM-BOILER FURNA-CES.

Specification forming part of Letters Patent No. 21,644, dated October5, 1858.

T0 @ZZ whom t may concern:

Be it known that I, JAMES ALcoEN, J r., of Charlestown, in the county ofMiddlesex and State of Massachusetts, have invented certain new anduseful Improvements in BoilerFur naces; and I do hereby declare that thefollowing is a full, clear, and exact description of the same, referencebeing had to the accompanying drawings, making part of thisspecification7 in which- Figure l is a central ^longitudinal verticalsection of a boiler-furnace constructed ac- Fig. 2 is a transversevertical section of the same in the plane indicated by the line a: Qc,Fig. l. Fig. 3 is a longitudinal vertical section of the same in theplane indicated by the line y y, Fig. 2. Fig. 4 is a horizontal sectionof the same in the plane indicated by the line e' ,e of Fig. l.

Similar letters of reference indicate corresponding parts in the severalfigures.

This invention consists in a novel arrangement of passages for thepurpose of causing the return from the back part of the furnace and fromthe lower part of the smoke-stack to the ash-pit of considerableportions of the smoke and inflammable matters escaping from thefire-box, and the consumption of those matters by causing them to passthrough the fire on the grate with the fresh air admitted to produce thecombustion of the fuel on the grate.

To enable others skilled in the art to make and use my invention, I willproceed to describe its construction and operation.

K is the boiler, which may be of any construction, butis shown as aplain cylinder.

K is thesetting.

A is the tire-chamber and A3 the grate, with a {ire-bridge A at the backof the grate, and B is an air-tight chamber in rear of the firebridgehaving no direct communication with the tire-chamber.

C is a false bridge-wall under the rear of the boiler, made with lthreeseparate cavities C C2 C, the tirstmentioned one C extending all acrossthe bottom of the setting and communicating with the last-mentioned oneC3, which is close under the boiler, by means of two upright sidepassages C4 C4, which are outside of the central cavity C2. The lowestcavity C has an entrance I from the main Iiue U, which extends from thefire-bridge A to the false bridge C,and this entrance I, with thepassages C4 C1t and two holes I I in the back of the chamber, constitutethe means of direct communication from the fire-chamber to thesmoke-stack S. The cavity C2 has an aperture T, communicating with themain Hue U, and furnished with a damper T', operated by a lever T2outside the furnace, and from the bottom of the said cavity theredescend two pipes G G, which are elbowed or bent to run forward andenter the chamberB in rear of the fire-bridge. From the chamber B twopipes E E, doubly elbowed, enter the ash-pit A2.

D is an uprightpipe arranged within the lower part of the smoke-stack,at the bottom of which it connects with ahorizontal pipe H, which runsinto the box B. This pipe D, which is open at the top, is contracted inta perform in a downward direction.

V is a cover placed over the mouth of said pipe D, but a little elevatedabove the said mouth, so as to leave an entrance thereinto, said coverbeing made of much larger diameter than said mouth, so as to leave but asmall passage outside of itin the smoke-stack, and being made concave onits under side.

The operation is as follows: Fire having been made in the usual wayonthe grate and having got well started,there is adirect draft through themain flue U, passages I, C4, and I into the smoke-stack, and the heavierportions of the gases take this course, while the lighter and morecombustible gas (carbonio oxide) keeping in the upper part of the mainflue U, escapes through the aperture T, chamber C2, and pipes G G to thechamber B, whence it is conveyed to the ash-pit A2 by the pipes E E, andwith the air entering the ash-pit passes up through the heated fuel onthe grate and is consumed. A portion of the unconsumed gases enteringthe smoke-stack by the course first described is collected by the coverV of the coue-pipe D and thereby deflected into the said pipe andconveyed into the pipes G, and through it to the chamber B, whence itescapes by the pipes E E to the ash-pit to be supplied to the iire alongwith that passing through the pipes'G G.

2. The arrangement of the oone pipe D with its delectingcoverV and thepipe I-Lin com.- bination With the chamber B, arranged in rear of andcommunica-ting with the ash-pit,

substantially as and for the purpose described.

l JAMES ALooRN, JR.

Witnesses:

GEO. P. KETTELL, GEO. B. THOMAS.

